Peter Hammill - "Something About Ysabel's Dance", "A Way Out", "Curtains", "Incomplete Surrender", "Given Time", "Gaia", "Your Tall Ship", "A Better Time", "Come Clean", "Phosphorecence", "Bareknuckle Trade"... (Hammill is a master of ballads)
King Crimson - Walking on Air, One Time (two tracks off THRAK)
Spock's Beard - "Ghosts of Autumn", "Carry On", "Watching the Tide" (all three without Neal Morse)
Neal Morse - "I Am Willing" (perhaps Neal Morse's strongest ballad ever, off "Testimony")
Iona - "Wave after Wave" (great band, gorgeous song from their 2000 album "Open Sky")
Guy Manning - "The River of Time" (Manning is a modern prog troubadour with lots of ballads in his repertoire, this one is from the album "A Matter of Life & Death")